MES or ERP: what a manufacturing SME really needs
MES or ERP: what a manufacturing SME really needs
In short: it is not a choice between the two. The ERP runs the company: orders, purchasing, stock, accounting. The MES runs the shop floor: what each machine is doing, which order is running, how many good parts came out. A manufacturing SME almost always starts with the ERP and finds it needs the second when questions about the shop floor stay unanswered.
What the ERP does, and where it stops
The ERP (enterprise resource planning) thinks in transactions: a customer order, a production order, a stock movement, an invoice. It is the right system for knowing what must be produced and by when.
It stops at the shop floor door. The ERP does not know that the press stopped twenty minutes ago, that the setup is taking twice as long as planned, or that the order marked "in progress" is actually waiting for material. That information arrives, if it arrives, at the end of the shift and by hand.
What the MES does
The MES (manufacturing execution system) works at the pace of the machines. In the ISA-95 standard it sits between the machines and the ERP, and it answers questions such as:
- Which machines are producing now, and which are stopped?
- How far along is the order, and will it be on time?
- How much time went into setups, stops and waiting?
- How many good parts and how much scrap, per machine and per order?
The live status of every resource in DigiFactor. Demo data.
The differences, side by side
| ERP | MES | |
|---|---|---|
| Horizon | Days, weeks, months | Seconds, minutes, shifts |
| Unit of work | Order, document, transaction | Machine, activity, part |
| Source of data | People typing | Machines, sensors and operators |
| Typical question | "What must we deliver this month?" | "Why is line 2 late today?" |
| Who uses it | Administration, purchasing, sales | Production, maintenance, quality |
Five signs the ERP is no longer enough
- You learn the status of an order by walking the floor or phoning the shift leader.
- The standard times in the ERP do not match the real ones, and nobody knows by how much.
- OEE is calculated at the end of the month in a spreadsheet, when it is too late to act.
- Machine stops are remembered, not recorded, with no cause attached.
- The plan is redone every morning, because yesterday's plan did not hold.
If two or three of these sound familiar, the shop floor layer is what you are missing.
What to look for in an MES for an SME
- Machine connection without custom projects. Standard protocols such as OPC UA, Modbus, Siemens S7 and MQTT, and operator terminals where a machine cannot supply data.
- Integration with the ERP you already have. The MES reads orders and activities from the ERP and does not replace it.
- One data model. Production, maintenance, quality and energy should look at the same machines and the same orders, not at four separate databases.
- Growth by modules. Start with monitoring and add the rest when you need it.
- Numbers you can defend. What the machine detects and what the operator declares must sit together.
Production planning in DigiFactor, on the same orders that come from the ERP. Demo data.
Where DigiFactor fits
DigiFactor is an industrial operations platform: it covers the functions of an MES and goes further. The modules for production monitoring, planning, maintenance, quality and energy share one data model with your machines and your ERP, and two AI agents answer shop-floor questions and cite their sources.
Read more: MES software for manufacturing SMEs.
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